It is bouy number 3 marking the channel into a harbor. Odd numbered bouys are normally green and on the left side as you enter the harbor.
go around it on either side
I think you should----Keep the buoy on your port (left) side.
lp
As you enter a harbor from the open sea, you see a lighted buoy bearing the number 3. How should you pass it?
A green lighted buoy with the number 3 typically indicates a navigational aid used in maritime settings. It signifies a safe channel for vessels, marking the starboard (right) side of the channel when approaching from the sea. The number on the buoy helps mariners identify their position and ensure safe navigation. In the United States, such buoys follow the IALA (International Association of Lighthouse Authorities) system, where even-numbered buoys are green and denote safe passage.
A boat should cruise between a green and red buoy. The red buoy will always be located on the right side of your boat. Red buoys will always mean , returning, red, and right. There will be a number on a red buoy that will give the chart location. The numbers will always be even.
Do not pass between the buoy and the shore
When you see a green lighted buoy with the number 3, it indicates a safe navigational mark. This buoy typically marks the right side of a channel when returning from open sea, so you should keep it on your starboard (right) side as you navigate. Ensure you maintain a safe distance from the buoy and monitor your surroundings for other vessels and navigational hazards.
Keeping it on your port, passing it to starboard, will prevent your running aground.
Danger.
A yellow buoy in the water means caution. They can mean there is danger of pipes, dredge lines or other dangers.
When you see a green lighted buoy with the number 3, it indicates a channel marker that typically signifies a safe navigational route. You should keep the buoy on your starboard (right) side when proceeding in the direction of the channel. Always maintain awareness of your surroundings and other vessels while navigating. If unsure, consult your nautical charts for additional guidance.